package timenlp

type Lunar struct {
	IsLeap bool
	Day    int
	Month  int
	Year   int
}

type Solar struct {
	Day   int
	Month int
	Year  int
}

func NewSolarFromInt(g int) Solar {
	y := int((10000*g + 14780) / 3652425)
	ddd := g - (365*y + int(y/4) - int(y/100) + int(y/400))
	if ddd < 0 {
		y -= 1
		ddd = g - (365*y + int(y/4) - int(y/100) + int(y/400))
	}
	mi := int((100*ddd + 52) / 3060)
	mm := (mi+2)%12 + 1
	y += int((mi + 2) / 12)
	dd := ddd - int((mi*306+5)/10) + 1
	return Solar{
		Year:  y,
		Month: mm,
		Day:   dd,
	}
}

func (s Solar) ToInt() int {
	m := (s.Month + 9) % 12
	y := s.Year
	y -= int(m / 10)
	return 365*y + int(y/4) - int(y/100) + int(y/400) + int((m*306+5)/10) + (s.Day - 1)
}

type LunarSolarConverter struct {
	// 1888~2111年农历数据表
	// 农历数据 每个元素的存储格式如下
	// 16~13    12          11~0
	// 闰几月 闰月日数  1~12月份农历日数(大小月)
	// 注：1、bit0表示农历1月份日数，为1表示30天，为0表示29天。bit1表示农历2月份日数，依次类推。
	// 2、bit12表示闰月日数，1为30天，0为29天。bit16~bit13表示第几月是闰月(注：为0表示该年无闰月)
	// 数据来源参考: http://data.weather.gov.hk/gts/time/conversion1_text_c.htm
	LunarMonthDays []int
	// 额外添加数据，方便快速计算阴历转阳历 每个元素的存储格式如下：
	// 12~7         6~5    4~0
	// 离元旦多少天  春节月  春节日
	Solar []int
}

func NewLunarSolarConverter() *LunarSolarConverter {
	return &LunarSolarConverter{
		LunarMonthDays: []int{
			1887, 0x1694, 0x16aa, 0x4ad5, 0xab6, 0xc4b7, 0x4ae, 0xa56, 0xb52a,
			0x1d2a, 0xd54, 0x75aa, 0x156a, 0x1096d, 0x95c, 0x14ae, 0xaa4d, 0x1a4c, 0x1b2a, 0x8d55,
			0xad4, 0x135a, 0x495d,
			0x95c, 0xd49b, 0x149a, 0x1a4a, 0xbaa5, 0x16a8, 0x1ad4, 0x52da, 0x12b6, 0xe937, 0x92e,
			0x1496, 0xb64b, 0xd4a,
			0xda8, 0x95b5, 0x56c, 0x12ae, 0x492f, 0x92e, 0xcc96, 0x1a94, 0x1d4a, 0xada9, 0xb5a, 0x56c,
			0x726e, 0x125c,
			0xf92d, 0x192a, 0x1a94, 0xdb4a, 0x16aa, 0xad4, 0x955b, 0x4ba, 0x125a, 0x592b, 0x152a,
			0xf695, 0xd94, 0x16aa,
			0xaab5, 0x9b4, 0x14b6, 0x6a57, 0xa56, 0x1152a, 0x1d2a, 0xd54, 0xd5aa, 0x156a, 0x96c,
			0x94ae, 0x14ae, 0xa4c,
			0x7d26, 0x1b2a, 0xeb55, 0xad4, 0x12da, 0xa95d, 0x95a, 0x149a, 0x9a4d, 0x1a4a, 0x11aa5,
			0x16a8, 0x16d4,
			0xd2da, 0x12b6, 0x936, 0x9497, 0x1496, 0x1564b, 0xd4a, 0xda8, 0xd5b4, 0x156c, 0x12ae,
			0xa92f, 0x92e, 0xc96,
			0x6d4a, 0x1d4a, 0x10d65, 0xb58, 0x156c, 0xb26d, 0x125c, 0x192c, 0x9a95, 0x1a94, 0x1b4a,
			0x4b55, 0xad4,
			0xf55b, 0x4ba, 0x125a, 0xb92b, 0x152a, 0x1694, 0x96aa, 0x15aa, 0x12ab5, 0x974, 0x14b6,
			0xca57, 0xa56, 0x1526,
			0x8e95, 0xd54, 0x15aa, 0x49b5, 0x96c, 0xd4ae, 0x149c, 0x1a4c, 0xbd26, 0x1aa6, 0xb54,
			0x6d6a, 0x12da, 0x1695d,
			0x95a, 0x149a, 0xda4b, 0x1a4a, 0x1aa4, 0xbb54, 0x16b4, 0xada, 0x495b, 0x936, 0xf497,
			0x1496, 0x154a, 0xb6a5,
			0xda4, 0x15b4, 0x6ab6, 0x126e, 0x1092f, 0x92e, 0xc96, 0xcd4a, 0x1d4a, 0xd64, 0x956c,
			0x155c, 0x125c, 0x792e,
			0x192c, 0xfa95, 0x1a94, 0x1b4a, 0xab55, 0xad4, 0x14da, 0x8a5d, 0xa5a, 0x1152b, 0x152a,
			0x1694, 0xd6aa,
			0x15aa, 0xab4, 0x94ba, 0x14b6, 0xa56, 0x7527, 0xd26, 0xee53, 0xd54, 0x15aa, 0xa9b5, 0x96c,
			0x14ae, 0x8a4e,
			0x1a4c, 0x11d26, 0x1aa4, 0x1b54, 0xcd6a, 0xada, 0x95c, 0x949d, 0x149a, 0x1a2a, 0x5b25,
			0x1aa4, 0xfb52,
			0x16b4, 0xaba, 0xa95b, 0x936, 0x1496, 0x9a4b, 0x154a, 0x136a5, 0xda4, 0x15ac,
		},
		Solar: []int{
			1887, 0xec04c, 0xec23f, 0xec435, 0xec649, 0xec83e, 0xeca51, 0xecc46, 0xece3a,
			0xed04d, 0xed242, 0xed436, 0xed64a, 0xed83f, 0xeda53, 0xedc48, 0xede3d, 0xee050, 0xee244, 0xee439,
			0xee64d,
			0xee842, 0xeea36, 0xeec4a, 0xeee3e, 0xef052, 0xef246, 0xef43a, 0xef64e, 0xef843, 0xefa37, 0xefc4b,
			0xefe41,
			0xf0054, 0xf0248, 0xf043c, 0xf0650, 0xf0845, 0xf0a38, 0xf0c4d, 0xf0e42, 0xf1037, 0xf124a, 0xf143e,
			0xf1651,
			0xf1846, 0xf1a3a, 0xf1c4e, 0xf1e44, 0xf2038, 0xf224b, 0xf243f, 0xf2653, 0xf2848, 0xf2a3b, 0xf2c4f,
			0xf2e45,
			0xf3039, 0xf324d, 0xf3442, 0xf3636, 0xf384a, 0xf3a3d, 0xf3c51, 0xf3e46, 0xf403b, 0xf424e, 0xf4443,
			0xf4638,
			0xf484c, 0xf4a3f, 0xf4c52, 0xf4e48, 0xf503c, 0xf524f, 0xf5445, 0xf5639, 0xf584d, 0xf5a42, 0xf5c35,
			0xf5e49,
			0xf603e, 0xf6251, 0xf6446, 0xf663b, 0xf684f, 0xf6a43, 0xf6c37, 0xf6e4b, 0xf703f, 0xf7252, 0xf7447,
			0xf763c,
			0xf7850, 0xf7a45, 0xf7c39, 0xf7e4d, 0xf8042, 0xf8254, 0xf8449, 0xf863d, 0xf8851, 0xf8a46, 0xf8c3b,
			0xf8e4f,
			0xf9044, 0xf9237, 0xf944a, 0xf963f, 0xf9853, 0xf9a47, 0xf9c3c, 0xf9e50, 0xfa045, 0xfa238, 0xfa44c,
			0xfa641,
			0xfa836, 0xfaa49, 0xfac3d, 0xfae52, 0xfb047, 0xfb23a, 0xfb44e, 0xfb643, 0xfb837, 0xfba4a, 0xfbc3f,
			0xfbe53,
			0xfc048, 0xfc23c, 0xfc450, 0xfc645, 0xfc839, 0xfca4c, 0xfcc41, 0xfce36, 0xfd04a, 0xfd23d, 0xfd451,
			0xfd646,
			0xfd83a, 0xfda4d, 0xfdc43, 0xfde37, 0xfe04b, 0xfe23f, 0xfe453, 0xfe648, 0xfe83c, 0xfea4f, 0xfec44,
			0xfee38,
			0xff04c, 0xff241, 0xff436, 0xff64a, 0xff83e, 0xffa51, 0xffc46, 0xffe3a, 0x10004e, 0x100242,
			0x100437,
			0x10064b, 0x100841, 0x100a53, 0x100c48, 0x100e3c, 0x10104f, 0x101244, 0x101438, 0x10164c,
			0x101842, 0x101a35,
			0x101c49, 0x101e3d, 0x102051, 0x102245, 0x10243a, 0x10264e, 0x102843, 0x102a37, 0x102c4b,
			0x102e3f, 0x103053,
			0x103247, 0x10343b, 0x10364f, 0x103845, 0x103a38, 0x103c4c, 0x103e42, 0x104036, 0x104249,
			0x10443d, 0x104651,
			0x104846, 0x104a3a, 0x104c4e, 0x104e43, 0x105038, 0x10524a, 0x10543e, 0x105652, 0x105847,
			0x105a3b, 0x105c4f,
			0x105e45, 0x106039, 0x10624c, 0x106441, 0x106635, 0x106849, 0x106a3d, 0x106c51, 0x106e47,
			0x10703c, 0x10724f,
			0x107444, 0x107638, 0x10784c, 0x107a3f, 0x107c53, 0x107e48,
		},
	}
}

func (l *LunarSolarConverter) LunarToSolar(lunar Lunar) Solar {
	days := l.LunarMonthDays[lunar.Year-l.LunarMonthDays[0]]
	leap := l.GetBigInt(days, 4, 13)
	var offset int
	loopEnd := leap
	if !lunar.IsLeap {
		if lunar.Month <= leap || leap == 0 {
			loopEnd = lunar.Month - 1
		} else {
			loopEnd = lunar.Month
		}
	}
	var idx int
	for idx <= loopEnd {
		v := l.GetBigInt(days, 1, 12-idx)
		if v == 1 {
			offset += 30
		} else {
			offset += 29
		}
	}
	offset += lunar.Day
	solarTmp := l.Solar[lunar.Year-l.Solar[0]]
	solar := Solar{
		Year:  l.GetBigInt(solarTmp, 12, 9),
		Month: l.GetBigInt(solarTmp, 4, 5),
		Day:   l.GetBigInt(solarTmp, 5, 0),
	}
	return NewSolarFromInt(solar.ToInt() + offset - 1)
}

func (l *LunarSolarConverter) GetBigInt(data int, length int, shift int) int {
	return (data & (((1 << length) - 1) << shift)) >> shift
}
